1. Field of the Invention
The present invention generally relates to a method and apparatus for automatically converting a phone number while roaming, and more particularly, to a method of automatically converting a phone number while roaming whereby a roaming user in a foreign country can conveniently call a recipient in a home country using a phone number stored in a mobile communication terminal, and a mobile communication terminal using the method.
This work was supported by the IT R&D program of MIC/IITA.[2006-P10-41, A Study on Standardization for Implementation of Number Portability]
2. Description of the Related Art
Recently, international roaming services for sharing communication base stations among common carriers and providing connection of mobile calls to mutual subscribers have been provided. An international roaming service assigns a unique international roaming number to an individual user in order to enable the user to make a phone call using a mobile communication terminal anywhere around the world.
A conventional international roaming service of a mobile communication terminal is of a service type in which a common carrier in a corresponding country (or visited country) provides a communication service at the request for a roaming service from a mobile communication subscriber, which will hereinafter be referred to as a user, in a home country on condition that a common carrier in the home country makes a roaming contract with the common carrier in the visited country. International roaming services can be classified into automatic roaming services and rental roaming services. An automatic roaming service provides a communication service to a user staying in the visited country in order to allow the user to continue using a mobile communication terminal used in the home country and a rental roaming service provides a communication service of the visited country by renting a separate roaming mobile communication terminal to the user.
After a general process of calling a recipient in a home country using a roaming service in a visited country is described, a conventional technology related to the present invention will be described.
The general process for the roaming user in the visited country to call the recipient in the home country is performed as follows.
The user first inputs a prefix for connection from the visited country to the home country and then inputs a phone number of the recipient, thereby being connected to the recipient in the home country. The prefix is generally composed of an international dialing code of the visited country and a country code of the home country. The international dialing code is 001, 002, 00700, 00365, or the like in Korea and is 011 in the U.S. The international dialing code may vary according to international phone service operators like in Korea. As a result, according to the general process, the user has to input the international dialing code of the visited country and the country code of the home country each time the user calls the recipient in the home country and has to memorize the international dialing code of the visited country and the country code of the home country at all times.
The present invention particularly relates to a way to extend a method of placing a call using a phone number stored in a memory of a mobile communication terminal to a roaming case. Examples of the method of placing a call using a phone number stored in a memory of a mobile communication terminal, which hereinafter will be referred to as a memory-based calling method, may include a first memory-based calling method whereby a user selects a phone number of a desired recipient from a phone number directory displayed on a screen of the mobile communication terminal, a second memory-based calling method whereby the user selects a recent calling phone number or a recent called phone number stored in the memory to place a call, and a third memory-based calling method whereby upon of the user pressing a hot key, a phone number corresponding to the pressed hot key is selected from among phone numbers stored in the memory in order to place a call to a desired recipient.
Conventional methods of calling a recipient in a home country using a phone number stored in a memory of a mobile communication terminal will be described below.
According to a first conventional method, a user searches for a phone number in a memory of a mobile communication terminal and notes down or memorizes the found phone number. The user then inputs the prefix and inputs the noted-down or memorized phone number, to thereby contact a recipient in a home country. However, since this method cannot take advantage of the memory-based calling method, the user has to note down or memorize the found phone number, remember the prefix for every call, and directly input the prefix.
According to a second conventional method, each time a user places a call to a home country, the user downloads software for roaming users over a mobile phone network, executes the downloaded software, and selects a phone number of a recipient in the home country from a phone number directory displayed on a screen of a mobile communication terminal. In other words, the downloaded and executed software converts the selected phone number. However, the second conventional method has the following programs. First, the user has to separately input a command for software downloading to the mobile communication terminal and the software downloading incurs additional cost. Second, for every call, the user has to separately input a command for software execution to the mobile communication terminal. Third, the background screen of the mobile communication terminal changes for dialing after software execution. Fourth, the user cannot select a desired international phone service operator because the user can use only an international phone service operator designated by software.
Therefore, there is a need for a technique for overcoming the above-described problems and allowing a roaming user in a visited country to make the most use of advantages of the memory-based calling method in order to talk with a recipient in a home country.